Lee S T, Park S K, Lee H, Lee J S, Park Y W
Department of Biochemistry, College of Science, Yonsei University, Seoul, Korea.
Jpn J Hum Genet. 1997 Dec;42(4):499-505. doi: 10.1007/BF02767026.
Tyrosinase-related oculocutaneous albinism (OCA1), an autosomal recessive inborn error of pigmentation, is caused by the deficiency of tyrosinase. We had previously identified two different mutations of the TYR gene in a four year old Korean male with mild OCA; a P310insC frameshift in exon 2 and an IVS2-7t-->a,-10-11deltt splice junction mutation in exon 3. Here we report a prenatal diagnostic study of a subsequent fetus of the above family that was at 25% risk of OCA1. SSCP/heteroduplex screening, restriction enzyme digestion, and allele-specific oligonucleotide hybridization analyses of DNA obtained by chorionic villus sampling indicated that the fetus was a compound heterozygote for the paternal P310insC and the maternal IVS2-7t-->a,-10-11deltt mutations. The diagnosis was later confirmed by observation of poorly pigmented irides of the abortus terminated at the 18th week of gestation. This approach provides a fast and reliable method for DNA-based prenatal diagnosis when specific mutations are known in families at high risk of OCA1.
酪氨酸酶相关的眼皮肤白化病（OCA1）是一种常染色体隐性遗传性色素沉着先天性疾病，由酪氨酸酶缺乏引起。我们之前在一名患有轻度OCA的4岁韩国男性中鉴定出TYR基因的两种不同突变；外显子2中的P310insC移码突变和外显子3中的IVS2-7t→a，-10-11deltt剪接连接突变。在此，我们报告了对上述家庭中一名后续胎儿进行的产前诊断研究，该胎儿患OCA1的风险为25%。对绒毛取样获得的DNA进行单链构象多态性/异源双链体筛选、限制性酶切和等位基因特异性寡核苷酸杂交分析表明，该胎儿是父本P310insC和母本IVS2-7t→a，-10-11deltt突变的复合杂合子。后来通过观察妊娠第18周终止妊娠的流产胎儿色素沉着不良的虹膜，证实了诊断。当在OCA1高风险家庭中已知特定突变时，这种方法为基于DNA的产前诊断提供了一种快速可靠的方法。
